Antifungal Activity of Thyme and Carvacrol Nanoemulsions Against Aspergillus fumigatus Isolated from Different Types of Cheese

Abstract

The control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit the fungal spoilage in dairy products. Therefore, the aim of this study is controlling Aspergillus fumigatus isolated from cheese by safe, non-allergic and natural food preservative nano-emulsions. Two hundred cheese samples of four different types (50 each) were studied for the presence of A. fumigatus. The isolated strains were examined for their ability to growth under the effect of two natural nano-emulsion as thyme (TN) and carvacrol (CN) nanoemulsions using well diffusion method (WDM). The possible changes in the fungus structure were described by scanning electron microscope (SEM). The nanoemulsions were prepared and characterized by transmission electron microscope (TEM). The incidence of A. fumigatus in different types of cheese was detected with percentage of 24, 6 and 12 % in Kareish, Damietta and Processed cheeses, respectively and could not be detected in Cheddar cheese. Results show a significant inhibitory effect of CN than TN on A. fumigatus growth with distinctive destruction in its ultrastructure. Applications of CN in the dairy industry will be a market trend to improve cheese quality by their antifungal properties and enhancement their shelf life.